It is indeed not set in the 32bit kernel but it can be turned on.
First copy your current running kernel config
zcat /proc/config.gz > /usr/src/linux/config
to get a nice kernel config menu.
Use the cursor keys to go down to the option Power management and ACPI options --->
and hit "Enter"
Now cursor down to < > APM (Advanced Power Management) BIOS support --->
and hit "Space" twice
The < >
should now be <*>
which means it will be built into the kernel
Now hit ESC twice in quick succession and then do it again (4 times in total) and you should have a dialog asking you to save changes
The default is Yes so you can just hit "Enter" here.
Now you need to kick off the build by typing "make" and hit Enter.
At this point given the specs of the machine you gave you might want to find something else to do for a while and this will take some time ..............
Once it does finish you'll find you nice new kernel as arch/x86/boot/bzImage copy that file over to /boot
Create yourself a new entry in /etc/lilo.conf to boot it (just copy your current kernel section over and change the "image" and "label" sections to suit
Now run lilo
Then reboot and select the new kernel and see how it goes, if it works ok you can then set lilo to boot in by default (lilo boots the first kernel as the default)